The present invention relates generally to semiconductor manufacturing equipment, and more particularly, to a photolithography system for use in the manufacture of semiconductor integrated circuit devices.
In conventional photolithography systems, the photolithography equipment requires a patterned mask to print a mask pattern on a photo resist coated surface or subject. The subject may include, for example, a semiconductor substrate. The conventional patterned mask or photomask may include, for example, a quartz glass mask. In addition, with the conventional photolighographic system, a photo resist coated subject must be aligned to the mask very accurately using some form of mechanical control and sophisticated alignment mechanism. The cost of the conventional patterned mask is very expensive also, in addition to a typically very long mask purchase lead time. The long mask purchase lead time is not very helpful when a short product development cycle is desired. Still further, if a particular mask design is found to require a design change in the pattern, no matter how small of a change, then mask modification cost and a respective lead time to implement the required change can cause serious problems in the manufacturing of the desired product.
In typical integrated circuit design activity, a particular mask may be modified or undergo modification on the order of seven to eight times, maybe even more, before completion of the design activities associated with a particular integrated circuit. Naturally, total cost of making the mask is very expensive and can become cost prohibitive. In addition, a corresponding total lead time becomes very long as a result.
Still further, in conventional photolithography systems for integrated circuit fabrication and other applications, such as printed circuit board manufacturing, the use of a printed mask is required for disposing a desired mask pattern onto a resist coated subject. The printed mask is typically made at a mask printing manufacturer or mask shop, for example, with the use of a very sophisticated electron beam direct writing system or photography system to print a desired design pattern onto a transparent substrate material, such as a quartz glass plate. In addition, highly sophisticated computer systems may also be necessary.
With respect to the manufacture of semiconductor integrated circuit devices, for example, one disadvantage with the use of a conventional patterned mask is that conventional patterned masks increase the manufacturing cost of the semiconductor integrated circuit devices. The use of conventional patterned masks furthermore undesirably lengthens a manufacturing cycle time in terms of a given mask purchase cycle time. Mask purchase cycle time includes the time involved in the purchasing of a desired mask from a mask vendor for use in the patterning of a photo resist coated surface. Still further, with a conventional patterned mask, when light is directed through the pattern thereof, for example where the pattern includes sub-micron slits and feature sizes, the light is subject to being diffracted in an undesirable manner. As a result, a complicated lens system is required to compensate for the effects of the undesired diffracted light.
Referring briefly now to FIG. 1, a conventional photolithography system 10 is illustrated. The photolithography system 10 includes a light source 12, a first lenses system 14, a printed mask 16, a mask alignment system 18, a second lenses system 20, a subject 22, and a subject alignment system 24. Subject 22 includes a photo resist coating 26 disposed thereon. During photolithography, light 28 emanates from the light source 12, through the first lenses system 14, the printed mask 16, the second lenses system 20, and onto the subject 22. In this manner, the pattern of the mask 16 is projected onto the resist coating 26 of the subject 22.
It would thus be desired to provide a photolithography system and method which overcomes the above mentioned problems in the art.